The movement patterns of two populations of Twites Carduelis flavirostris in Ireland

  • June 1, 2010
  • by Derek McLoughlin , Chris Benson , Bryony Williams & Don Cotton

The Twite Carduelis flavirostris is one of only three passerines included on the red list of Birds of Conservation Concern in Ireland. As part of a study on its ecology, we investigated the local movement patterns of two populations of Twites in Counties Mayo and Donegal between January 2006 and July 2008. The breeding populations studied comprised over 40 of an estimated 54–110 breeding pairs in Ireland. Colour ringing was used to identify individual Twites in the field. In the course of this study, 492 birds were ringed, of which 480 were caught outside the breeding season; 57 (12%) were resighted on their breeding grounds. The breeding birds spent most of the winter season within 28 km of their breeding areas. We also describe the size and structure of the home ranges of 11 Twites radio tracked over four periods – March, May, June and August – on the Mullet Peninsula, County Mayo, in the northwest of Ireland. The results of this study suggest that Irish Twites are mainly sedentary and that their populations appear to be augmented by Scottish breeding birds during the winter months.